1. Field of the Invention
This invention relates to a folding structure, capable of passing from an unfolded position to a folded position, and vice versa, comprising telescopic uprights including each at least one lower element sliding with respect to an upper element integral with said structure, and which support a collection of mutually-adjacent prismatic box structures, and the walls of which consist of criss-cross longitudinal members articulated in the manner of scissors.
The invention also relates to an upright for forming such a structure.
This invention is related to the field of knockdown or folding structures designed to be used as a shelter.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Such a shelter generally consists of a metallic structure covered, at least in its upper portion, by a covering element forming a roof. Said shelter is most often, in the unfolded position, in the form of a tent having the shape of a cube surmounted by a pyramid.
This type of shelter is designed for a specific use, such as a stand or the like, over a certain period, requiring then assembly and disassembly, both simple and fast. This is why existing shelters have been designed to be unfolding, passing from a folded configuration, for their transport and their storage, to an unfolded position, or vice versa. This possibility to fold and unfold the shelter facilitates greatly its assembly in comparison with shelters comprising a structure consisting of longitudinal members, rods or bars that are removable and made integral to each other by means of fastening elements.
As to the folding shelter, it includes a structure generally consisting of longitudinal members made of a metallic material, for example of aluminum or aluminum compound sections, or also of composite material such as fiberglass or carbon fiber, or the like. Said longitudinal members are articulated between them so as to permit the passing of said shelter from a folded position to an unfolded configuration, or vice versa.
In addition, the covering element is secured to said structure so that the folding or the unfolding of the shelter does not require the removal of said covering element. To this end, the latter is made in the form of a tarpaulin made of textile or plastic material, or the like, flexible and waterproof, fastened to said structure.
However, the existing folding shelters are limited in dimensions because of the bearing capacity of the structure and the weight the articulated longitudinal members support as well as the overall weight of the structure. The existing shelters generally have a maximum ground area of 24 square meters. For larger areas, it is necessary to resort to classical knockdown shelters.
The implementation of large-size shelters, in the range of 5×5 meters or even more, offers its owner undeniable commercial advantages: great surface and volume capacity, a neat appearance, and excellent visibility. The last factor is particularly important while participating at exhibitions, where each exhibitor would like to distinguish himself from his neighbors, in particular by the volume and height of his installations.
In order to permit in particular an extension in height of such a shelter, it is advisable to design such shelters with a high structure comprising legs or uprights having a large size, or at least comprising an area that is higher than the rest, which then imposes using one or more poles.
The essential service stresses, subject to standardization in many countries, consist of:                wind load resistance;        resistance to a load of rain or snow which can accumulate on the roof of such a shelter.        
Such standards impose the evacuation of the public in case of exceeding the thresholds of wind speed or static load. Besides, it is in the owner's interest, in such a case, to reduce the wind contact surface, to relieve the roof from its shelter, and even to fold up or disassemble the latter very quickly if the conditions become extreme.
Such a structure, having a large surface and great height, is necessarily heavier and also more complex than a structure designed uniquely to permit, at ground level, the passage of the public, and the size of which is adjusted to the height standards for the circulation of persons.
In particular, the weight of a shelter having a large size, for example having a ground surface of 5×5 meters, is, even if light materials are used, a weight, in particular above 100 kg, that cannot be easily handled by one person.
Disadvantages related to the weight of a large structure are even more amplified by the expansion in height of the latter.